Optimizing object placements and initial buffer pool sizes

This topic describes how to optimize the object placements in buffer pools and buffer pool sizes on the client.

About this task

Related tasks:

Before you can use this function, you must have performed the tasks described in:
- Collecting data
- Creating activity reports and bpd files. Here, only bpd files are of interest.
- Downloading files from the host to the client
  A buffer pool data file must be available on the client (the file with the recommended file name extension bpd).

General remarks:

Your client should have at least 40 MB of available physical memory (random access memory) for this function. You can check this in the Windows Task Manager. Close other applications, if you receive an Out of memory message. Note that free memory requirements increase with the number of objects to be treated.
Example: 1 000 objects require approximately 60 MB, 25 000 objects require approximately 90 MB, 100 000 objects require approximately 230 MB, and 200 000 objects require more than 500 MB.
The data used for this function reflects the buffer pool activity for the interval for which trace data was collected and for the time frame that was specified with the GLOBAL and the BPACTIVITY command when the bpd file was created.
The bpd file used for the object placement function usually contains information about active and inactive objects. With the object placement function, you can specify whether to include the inactive objects (also called unused objects) in rule processing and object placement considerations. However, if inactive objects were explicitly excluded from the bpd file (by means of the BPACTIVITY FILE ACTIVEOBJECTS command), your specifications have no effect on the object placement result.
If you want to print the object placement results shown in your web browser, use your browser's printing capabilities to print the information. For colored printouts, check the browser settings.
Example: In the Internet Explorer, click Tools —► Internet Options —► Advanced. Under Printing, select Print background colors and images.
In Db2® Performance Expert for z/OS®, you can configure a different web browser. If required, click Monitor —► Configuration —► Preferences and follow the instructions.